Excel macro error when workbook is shared

[Giuseppe]

Hi - have an Excel 2003 macro (below) that works fine - until I share the workbook at which point it fails with 'Run-time error '1004': Application-defined or object-defined error' the first time it's run, subsequent runs generate 'Run-time error '-214714848 (80010108)': Automation error The object invoked has disconnected from its clients.' The macro is attached to a command button on the workbook and inserts a new row in a spreadsheet and extends two data validation ranges (all done by a macro recording in the first place). Works fine until the workbook is shared, where it fails after the 'Test_extend_range Macro' comment - any ideas?

Private Sub AddNewLineDateButton_Click()
  '
  ' AddNewLineDateButton Macro
  '
  '
  	Worksheets("Calls").Activate
  	Rows("13:13").Select
  	Selection.Insert Shift:=xlDown
  	Range("A13").Select
  	Rows("12:12").Select
  	Selection.Cut
  	Rows("13:13").Select
  	ActiveSheet.Paste
  	Dim DateTime As String
  	DateTime = Format(Date, "mm/dd/yy") & " " & Format(Time, "hh:mm")
  	Range("C12").Select
  	ActiveCell.Value = DateTime
  	Range("A12").Select
  
  ' Test_extend_range Macro
  
  	Range("A12:A13").Select
  	Range("A13").Activate
  	With Selection.Validation
  		.Delete
  		.Add Type:=xlValidateList, AlertStyle:=xlValidAlertStop, Operator:= _
  		xlBetween, Formula1:="=$A$7:$A$11"
  		.IgnoreBlank = True
  		.InCellDropdown = True
  		.InputTitle = ""
  		.ErrorTitle = ""
  		.InputMessage = ""
  		.ErrorMessage = ""
  		.ShowInput = True
  		.ShowError = True
  	End With
  	
  	Range("F12:F13").Select
  	Range("F13").Activate
  	With Selection.Validation
  		.Delete
  		.Add Type:=xlValidateList, AlertStyle:=xlValidAlertStop, Operator:= _
  		xlBetween, Formula1:="=$F$7:$F$8"
  		.IgnoreBlank = True
  		.InCellDropdown = True
  		.InputTitle = ""
  		.ErrorTitle = ""
  		.InputMessage = ""
  		.ErrorMessage = ""
  		.ShowInput = True
  		.ShowError = True
  	End With
  	Range("A12").Select
  	
  End Sub